Photodynamic therapy is a treatment method that uses a photosensitizing agent and irradiating light to destroy cells of interest in the body. When the photosensitizer is exposed to a specific wavelength of light, it produces a cytotoxic reactive oxygen species that can induce apoptosis, necrosis and/or autophagy of nearby cells.
Current photodynamic therapy methods rely on using antibodies or fragments thereof to localize the photosensitizing agent to the target cells. There is, however, a need for improved photosensitizing probes based on small molecule conjugates to induce apoptosis in target cells, e.g., diseased cells, in a subject using photodynamic therapy. The present invention satisfies this need and provides related advantages as well.